Anaemia (and iron deficiency?) in aortic stenosis--a bystander or a potential therapeutic target?

Evidence That Anemia Accelerates AS Progression Via Shear-Induced TGF-β1 Activation: Heyde's Syndrome Comes Full Circle

The severity of aortic stenosis (AS) is associated with acquired von Willebrand syndrome (AVWS) and gastrointestinal bleeding, leading to anemia (Heyde's syndrome). We investigated how anemia is linked with AS and AVWS using the LA100 mouse model and patients with AS. Induction of anemia in LA100 mice increased transforming growth factor (TGF)-β1 activation, AVWS, and AS progression. Patients age >75 years with severe AS had higher plasma TGF-β1 levels and more severe anemia than AS patients age <75 years, and there was a correlation between TGF-β1 and anemia. These data are compatible with the hypothesis that the blood loss anemia of Heyde's syndrome contributes to AS progression via WSS-induced activation of platelet TGF-β1 and additional gastrointestinal bleeding via WSS-induced AVWS.

Intravenous iron supplement for iron deficiency in patients with severe aortic stenosis scheduled for TAVI Results of the IIISAS randomised trial

Aims

The aim of this trial was to evaluate whether intravenous iron could provide benefit beyond transcatheter aortic valve implantation (TAVI) in iron‐deficient patients with severe aortic stenosis.

Methods and results

In this randomised, placebo‐controlled, double‐blind, single‐centre trial, we enrolled patients with severe aortic stenosis and iron deficiency (defined as ferritin <100 µg/L, or 100–299 µg/L with a transferrin saturation <20%) who were evaluated for TAVI. Patients were randomly assigned (1:1) to receive intravenous ferric derisomaltose or placebo ∼3 months before TAVI. The primary endpoint was the between‐group, baseline‐adjusted 6‐min walk distance measured 3 months after TAVI. Secondary outcomes included quality of life, iron stores, hand grip strength, New York Heart Association (NYHA) class, and safety. Between January 2020 and September 2021, we randomised 74 patients to ferric derisomaltose and 75 patients to placebo. The modified intention‐to‐treat population comprised the 104 patients who completed the 6‐min walk test at baseline and 3 months after successful TAVI. Iron stores were restored in 76% of the patients allocated to iron and 13% of the patients allocated to placebo (p < 0.001). There was no difference in the baseline‐adjusted 6‐min walk distance between the two treatment arms (p = 0.82). The number of serious adverse events, quality of life, hand grip strength, and NYHA class did not differ between the treatment arms.

Conclusion

Treatment with intravenous iron did not provide clinical benefit beyond TAVI in iron‐deficient patients with severe aortic stenosis.

Clinical Trial Registration: ClinicalTrials.gov NCT04206228.

Iron Deficiency as a Therapeutic Target in Cardiovascular Disease

Iron deficiency is the most common nutritional disorder in the world. It is prevalent amongst patients with cardiovascular disease, in whom it is associated with worse clinical outcomes. The benefits of iron supplementation have been established in chronic heart failure, but data on their effectiveness in other cardiovascular diseases are lacking or conflicting. Realising the potential of iron therapies in cardiovascular disease requires understanding of the mechanisms through which iron deficiency affects cardiovascular function, and the cell types in which such mechanisms operate. That understanding has been enhanced by recent insights into the roles of hepcidin and iron regulatory proteins (IRPs) in cellular iron homeostasis within cardiovascular cells. These studies identify intracellular iron deficiency within the cardiovascular tissue as an important contributor to the disease process, and present novel therapeutic strategies based on targeting the machinery of cellular iron homeostasis rather than direct iron supplementation. This review discusses these new insights and their wider implications for the treatment of cardiovascular diseases, focusing on two disease conditions: chronic heart failure and pulmonary arterial hypertension.